Abstract. Walnut (Juglans regia L.) - a medicinal plant with a variety of properties, which has great therapeutic potential in medicine. In the past two decades, there has been great interest in evaluating the phenolic content and antioxidant activity of various parts of the walnut. This contribution highlights and comparatively analyzes recent scientific work on the extraction and quantification of the bioactive content of walnut leaves. The current review article also attempted to describe the antioxidant content of phenolic extracts obtained from walnut leaves. As a result of a comparative analysis of the literature data on the chemical composition and evaluation of the effect of walnut leaves on the course of various diseases it was found that the leaves contain a greater amount of flavonoids, tannins and naphthoquinones, and leaf extracts have a positive effect on the recovery processes during diseases, which proves the feasibility of their use in medicine.